¿Afecta el pastoreo a las siguientes generaciones? Estudio de caso, efecto del ganado sobre la variabilidad genética de la progenie de Prosopis alpataco

C.P. SOUTO; M. TADEY; I. PELLIZA

Mendoza

Jornada; I Jornadas de Desertificación; 2018

ONDTyD y el IADIZA-CONICET

DOES GRAZING AFFECT NEXT GENERATIONS? A CASE STUDY ON THE EFFECT OF LIVESTOCK GRAZING ON GENETIC VARIATION OF PROSOPIS ALPATACO. Exotic livestock may decrease reproduction and population size of the plants they consume. Both effects can erode genetic variation of populations, affecting their evolutionary potential. Through genetic drift and inbreeding depression, the progeny may be even more affected than its progenitor population. If this occurs, we expect to find a greater difference in genetic variability between progenitor population and progeny as livestock density increases. To test this, we analyzed in 9 paddocks with 3 levels of livestock density (high, intermediate and low) the genetic variation of 30 individuals from parental and progeny populations in Prosopis alpataco, using isozyme electrophoresis technique. The effective number of alleles and the expected heterozygosis decreased as the stocking density increased, without differences among levels of stocking rate or generations. The heterozygosis increases in the progeny whereas the total divergence of both generations is different. We observed a tendency to the homogenization of genetic variability in the progeny, possibly due to bottleneck effects. Livestock decreases genetic diversity and increases population genetic structure affecting the evolutionary potential of the species through generations.Keywords: exotic livestock, expected heterozygosis, inbreeding, Monte Desert, shrubs.